Please help me to solve this problem

Question

Suppose that the functions g and h are defined for all real numbers x as follows:

g(x) = x+3

h(x) =2x+1

Write the expression for (g-h)(x) and (g+h)(x) and evaluate (g•h)(4).

Answer 1

g=x+3

h =2x+1

g-h = -x+2

g+h = 3x+4

g(4) = 7

h(g(4)) = h(7) =15